This section provides background information related to the present disclosure which is not necessarily prior art.
The functions of providing active/standby election, failover and switchover in safety critical systems for rail and public transportation applications are commonly provided as embedded functions within a computer system. Dual redundant, high availability systems provide backup for the above functions, but also within the architecture of the computer system. Off-the-shelf (COTS) computers lack these features and have therefore not been available for direct use for rail and public transportation fail-safe applications, thereby increasing the cost and complexity of the systems. Dual redundant systems producing signals that are each active at the same time would create safety concerns. Known systems also produce either a fixed voltage signal or a zero voltage, making determination of a “stuck” command signal difficult.